[EDITOR'S
NOTE: This story embargoed until Friday, November 7, 2003, to coincide
with publication in the Journal
of Urology.]

RESEARCHERS PINPOINT POSSIBLE CAUSE OF CHRONIC BLADDER DISEASE

COLUMBUS, Ohio – New research in cats suggests that the cause
of some cases of interstitial cystitis (IC) – a chronic and incurable
inflammatory bladder disease that affects at least 700,000 women in the
United States alone – may lie within the adrenal glands.

In a new study, researchers compared the adrenal glands of house cats
with feline IC to the adrenal glands of healthy cats and found that the
adrenals in the diseased cats were much smaller – nearly half the
size of those in the healthy cats.

Tony
Buffington

"Reduction in adrenal size has also been seen in people with chronic
fatigue syndrome, which can occur in conjunction with IC," said Tony
Buffington, lead author of the study and a professor of veterinary
clinical sciences at Ohio State University. "We don't know why
the adrenals were smaller in the cats with IC, but we think that the cats
were born with smaller-than-average glands.

The adrenal glands, which sit on top of the kidneys, are responsible
for a number of bodily functions, including hormone production and regulation
of heart rate and blood pressure. IC affects cats and humans in a similar
manner, and urologists believe that the feline urinary tract is one of
the best animal models for the human urinary tract.

"This suggests that
adrenal gland function in cats with IC may be relatively normal
under unstressed conditions, but it drops during periods of stress,"
Buffington said.

The researchers also found that, compared to healthy cats, the adrenal
glands of the diseased cats produced lower levels of the stress hormone
cortisol after the cats were injected with the stress-inducing compound
adrenocorticotropic hormone (ACTH). This suggests that the adrenal glands
in the cats with IC may not provide an adequate hormonal response during
stressful situations.

In humans, symptoms of IC include chronic pelvic pain, inflammation
of the bladder and increased urination frequency and urgency. Cats with
the disease also have noticeable urinary problems – they strain
when trying to urinate and also try to go frequently, often outside the
litter box.

The study appears in the December issue of the Journal of Urology.
Buffington conducted the research with Jodi Westropp and Kristin Welk,
both graduate students in veterinary clinical sciences at Ohio State.

The researchers evaluated how cats responded to an injection of a synthetic
form of the stress-inducing compound ACTH. Each cat (11 healthy controls
and 20 with IC) was given an injection of 0.125 milligrams of ACTH. The
researchers measured cortisol levels in the blood before and after ACTH
injection.

The adrenal glands in disease-free cats responded by producing normal
cortisol levels after ACTH injection, while the adrenals of cats with
IC produced about half as much cortisol in response to the stressor.

"This suggests that adrenal gland function in cats with IC may
be relatively normal under unstressed conditions, but it drops during
periods of stress," Buffington said.

The researchers also compared the size of the adrenal glands in 21 cats
– 13 cats had IC and 8 were disease-free. The adrenal glands of
the cats with IC averaged about half the size of the adrenals in the disease-free
cats.

If researchers find similar adrenal gland abnormalities in humans with
IC, they might be able to develop more effective treatments for the disease.
Although cortisol has been tried as a treatment with unsuccessful results,
the adrenal gland produces a variety of hormones that could play a role
in treating the disease.

"Since the causes of IC are unknown, physicians can only really
treat the symptoms, and the disease often returns," Buffington said.
"As for cats, not every cat with smaller-than-normal adrenal glands
will develop IC, and there are steps a cat owner can take to help prevent
the disease from developing, if their pet seems predisposed to IC."

Signs that a cat might be prone to IC include increased sensitivity
to its surroundings and also to sudden, loud sounds. Where a cat spends
much of its time may influence its chances of developing the disease.

"Cats restricted to indoor living are some five times more likely
to develop urinary problems than cats that are allowed outdoors,"
Buffington said. "I'm not debating whether cats should be housed
indoors or outdoors, but owners who choose to keep their cat inside should
create an enriched, stimulating environment for their pet.

Boredom may stress house cats, so owners need to make sure their cats
have an environment that is engaging and interesting.

Creating such an environment includes providing toys, hiding places
and perches for cats, as well as spending some time with the cat every
day. Buffington and his colleagues have created the Indoor Cat Initiative
program to help owners of indoor cats learn how to create a fuller environment
for their pet. Information on the program is online at www.nssvet.org/ici/index.php.